Tight carton



july 22, 1952 F. D. BERGSTEIN 2,604,252

TIGHT CARTON Filed April 9, 1947 2 SHEETS-SHEET l INVENTOR.

'HN/f PHI/lo Baos rem.

' GIZ' 7 July 22, 1952 F. D. BERGSTEIVN 2,604,252

TIGHT CARTON Filed April 9, 1947 2 SIlEETS-Sl-{EET 2 I l l l l l l: l. 7. f I l I I l l INVENTOR. .ICF-MNH BHV/a Benasrsnv.

BY Mw@ a HTTORNEYS.

, of liquid-proofing substance.

Patented July 22, 1952 2,604,252 lTIGHT CARTON Frank David Bergstein, Cincinnati, Olii'o Appia-ation Api-i1 9, 1947, serial No. 740,313 7 claims. (ci. 229-55) l I y AMy invention relates to paperboard packages which -are moisture tight, liquid tight, or gas `tight as desired, whichr comprise .a knock-down paperboard carton as the principal body element,

and which may be shipped and stored in the flat l condition.

Hithertok in the lprovision of cartons to hold Y liquids it has been the practice to provide a tubular-:paper carton which, after erection and closurey on one end, is dipped bodily into a bath This requires elaborate mechanism in the hands of the carton user, and it*v also results in ,an all-over coating of the proong substance within and without the structure. e '1 t In the provision of -g'as tight structures in which the contents may be packaged in a protective gaseous atmosphere, it has been suggested to provide over the whole exterior surface of the lled and closed package, a gas tight skin, covering, or membrane. This may be provided by an all over coating of skin forming treatments for the ends involving the applicationof. softened sealing substance Collapsible paperboard cartons have also been provided with interior tubular liners or bags which could be hermetically sealed at both ends.

In such structures, the bag or liner is the proofed container, while the carton is an external protective element.

It is an object of my invention to attain proofness in collapsible cartons in a new Way, having f many advantages, and being applicable to a wide variety of packagestructures.

It is an object of my invention to attain proof- `ness in collapsible structures in simpler ways whereby the cost' of such structures can be lowered, andwhereby the requiredequipment in Vthe hands of the carton user can be simplified are confined to the inside of the package and do not in any way interfere with or change its external appearance.

" These and other objects of my invention which will become apparent as the description proceeds,

lI accomplish in those structures and arrangements of parts and in those procedures of which I shall now describe certain exemplary embodiments. Referenceis made to the accompanying drawings wherein:

f substance, or byl a wrapping, or by a4 sleeve covering the body of the package 'together with Figure 1 is a plan view of a blank for a carton to be used in accordance with my invention. Figure 2 is a perspective view of an end sealing xture.

Figure 3 is a sectional view showing the fixture in use.` v

Figure 4 is a sectional view through one type of end seal formed in accordance with my invention. y y

Figure 5 is av sectional view showing another type of end sealing iixture in use.

Figure 6 is a partial perspective View showing the closed endv of one form of my package.

' Figure 7 is a vpartial plan view of another form of blank. I I

Figure 8 is a plan view of Aa blank With which a sheet of proofing material has been associated. Figure 8a is a partial plan view showing a more denite projectionro'fvv the liner sheet into the ilap area. I

Figure 9 is a plan view 'of a blankwith which a preformed tubular liner has been associated.

Figure 10 is a partialv sectional view showing an Vend seal in a lined carton.

Figure l1 is a partial sectional view showing ca. projecting, sealed liner end.-

.LFigure 12 is a partial sectional view illustrative of another mode of effecting 'an end seal.

Figure 13 is a partial sectional view showing one mode of securing a gas-tight condition at the longitudinal glue seam.- Y Y In the practice of myinvention, I provide a knock-down carton having the desired proofed characteristics as to its body portion. I then effect van end closure'and a seal, the latter by operationseffectiveon the inside of the package structure. In viewwofV the various elds of use to which different kcartons madein accordance with my invention may be put, .theclosure and seal just referred to may be made on one end of the carton only, andthe other end closed in some other fashion. Or both ends of the carton may be closed and sealed by operations such as those set forth, before or after filling. In one form of my invention, the effecting of a seal serves at the same time to bring about adhesive union of the folded end closure flaps.

Referring to Figure 1, I -have illustrated a carton -blank havingbody walls I, 2, 3, and ll, and a glue ilap 5, -in articulation along the usual longitudinal score lines.v The ends of the body walls are provided with closure ilaps 6 to I3 inf cluslve, articulated to the walls along the transverse score lines lll-and l5.

At one end of the carton, I may provide the short flaps 6 and 8 and the intermediate flap 'I with mating, small perforations I6 shown in dotted lines. At the other end of the carton, the short flaps I and I2 may be provided with cut-outs I1 and I8, while the flaps II and I3 have each a mating perforation I9 or 2D.

The carton will be made of paperboard, and will be so formed or processed as to have a body portion at least with the required proofness. Where the proofness desired is resistance against liquids or moisture, the proofness may be attained by treating the blank, or the board from which it is made, with a suitable proof-lng substance, of which there are many. The nature of the proofing substance is not a limitation upon this invention. Where a gas tight package .is desired, I prefer to proceed in other ways, someY of which will be set forth hereinafter, and involv4 ing the use of liner structures. Where the liner structures are substantially confined to the body walls of the carton, the mode of closure and sealing next described may be carried out in the same way. f A

The blank of Figure 1 will be tubed n the usual fashion by folding it on two intermediate longitudinal score lines with the adhesive union of the glue iiap to the free edge oi the body wall I. An adhesive having the required proofness will, of course, be used. In the collapsed tubular form the carton may be shipped to the user.

The user will erect or square up the carton body and will proceed to effect an end closure and seal. One way of doing this is to fold the fiaps I0 and I2 at one end of the carton, next the intermediate flap II, and finally the Iiap I3. These flaps can be adhesively secured together, and the adhesive may be applied during the operation of folding. The mating cut-outs I1 and I8 and the perforaticns I9 and 20 will come together to form a filling opening through the end of the carton.

A proofed condition of the end closure may be attained in accordance withv one aspect of my invention with the use of a sealing fixture shown in Figure 2. This comprises a base 2I and an upstanding columnar lmember 22 of a size to enter the holein the carton closure and project somewhat within the carton as illustrated in section in Figure 3.

The operation involves the formation of a seal, which is done by introducing into the carton a pipe o1' nozzle 23 and depositing upon the inside of the end closure a quantity of liquid proofing substance. The proofing substance as introduced should be freely owable, and its quantityshould. be sufficient to form a covering over the entire end closure portion of the carton. This covering may be made thick if desired to contribute to the physical strength of the carton end; but for sealing purposes it is only necessary to cover the entire carton closure interiorly with a film which bonds with the body walls of the carton. The proong substance should be applied in such quantity as to flow around the columnar member 22, but not" in suicient quantity to cover it.

Again the nature of the sealing substance does not form a limitation on this invention. and may be varied in accordance with the particular qualities of proofness desired. The fluidity may be attained by making a solvent solution of the proofing substance. But this will entail subsequent evaporation of the solvent, and I prefer to employ thermo-plastic sealing substances which may be rendered liquid by heat, and which will set rapidly. After the sealing substance has hardened, the fixture of Figure 2 may be withdrawn from the closed carton end, leaving a closure which has an opening in it as will be clear, but is otherwise in proofed or sealed condition.

Next the carton may be closed upon its opposite end by the folding of flaps 6 and 8, followed by the folding of the intermediate flap 'I and the final flap 9, together with the adhesive securement of these aps. This operation is followed by the effecting of a seal. The carton is positioned with the last closed end downwardly, and the nozzle or pipe 23 is introduced into it through the opening in the first made closure. Again a complete covering is made over` the closure, providing a proof iilm which is joined at its edges to the body Walls of the carton.

Where the flaps 6, 1, and 8 are provided with perforations as shown in dotted lines in Figure l, or are cut away at their edges or elsewhere to permit penetration of the sealing substance. the sealing substance may itself be used as the flap securing adhesive. In Figure 4, I have shownfat 24 a sealing coating which at 24a passes through the perforations I6, and, penetrating between the flaps, secures them together. Where this expedient is employed, it is necessary only to fold the flaps and effect the seal while holding them in folded condition. This expedient may also be adapted to the securing and sealing of the opposite end, i. e. the end formed of flaps I0 to I3 inclusive.

In the manner described above, I have now produced a carton which is closed at bothl ends, possesses the desired proofness for the use to which it is to be put, and has an opening through one of its end closures. It may be filled through this opening, and then may be closed in any suitable way. One way, is through the use of a shaped metal, plastic, or paperboard plug 25, which may be sealed in the opening in any suitable way (Figure 6). I prefer to dip theplug into molten proofing substance such as used in the seal, and then insert the plug. The molten coating on the plug will bond with the seal coating inside the container end, providing a tight and secure closure.

In the effecting of seals by my method, I prefer to take the following precautions. The sealing substance as introduced should` be as thinly liquid as is possible with the particular thermoplastic or settable substance chosen. VBy preheating the end of thecarton before injecting the sealing material, I further improve the quality of the seal and effecta saving ofthe flooding or sealing material. Sometimes thisfsaving, for comparable results, reaches fifty per cent. The reason appears to be that if the sealingv substance is introduced into the endof the container when the board is at normal room temperature it may tend to set before it flows into all of the crevices of the end closure, Where this occurs, it is likely to be found that more flooding material is needed to accomplish the same liquidtight or gas tight result. Further, I find that it is very desirable to rock the cartononce or twice in both directions, to assist in the distriburtionof the flooding or sealing material and to insure its entry into the corners of the end closure. The rocking is,.-of'course, accomplished at a time when the flooding'material is' still in a liquid and flowable condition.v The rocking may be accomplished by hand, orthe-containers may be engaged in cages with mechanism to provide a rocking action, that is to say a lowering of each of the four corners of the end closure of the carton successively. Y

By taking these precautions, dependable liquid tight seals are secured with no more than a teaspoon full of sealing substance in cartons of intermediate sizes, amounting to about twenty pounds of sealing material per thousand cartons.

The exact sequence of steps described above may be varied. For example, I may first fold the flaps 6 to 9, inclusive and effect a seal at their end of the carton. Then I may fold the flaps IU to I3 inclusive and up-end the carton over a fixture such as is shown in Figure 5. Like the fixture of VFigure 2, it has a base 2l and a column 22; but the column is perforated and is provided with interior members 26 for the delivery ofthe liquid proofing substance, and an external means 2l by which the device may be connected to a source of supply of the proofing substance. In .this way I may seal both ends of the carton with sealingmaterial introduced through only one end.

While I have described a form of carton having an opening through one end closure, the location of the opening may be changed. Thus I may provide an opening 28 in a body wall of the carton, in which event, the flaps ID to I3 may be made like the flaps 6 4to 9. The flaps at both ends of such a carton may be folded and held in closed position, whereupon I may effect seals successively at the two ends of the carton by resting the carton first on one end and then the other and introducingrthe sealing material by means of a curved spout or pipe projected into the carton through the hole 2B.

The size and shape of cartons made in accordance with my invention do not form a limitation on it. Likewise, the nature of the end closures can be widely varied. The type of imperforate end closure hereinabove described may be made at only one end of the carton and the other end may be closed after filling in some other fashion. For example, a carton may be made and used with my sealed closure at the bottom and, where employed for liquids, it may be closed with the familiar gable top closure in use on paper milk bottles. Again, in forming my sealed closures, the nature of theflaps and the manner of `their securement may be widely varied. Interlocking flaps may be employed as well as flaps so configured that when folded, depressed inwardly, and released, they automatically spring into interlocked position.

I may also employ an automatically selferecting end closure. Referring to Figure 7, I have shown flaps '29 to 32 on the ends of the body walls. Two of these flaps have triangular corner portions 33 and 34 demarked by diagonal score lines. Prior to the tubing of the carton, the end flaps will be folded inwardly with the triangular portions 33, and 34, reversely folded and treated with adhesive. The result of the tubing operation will be to cause these triangular portions to adhere to adjacent flaps. In the tubed carton, the end closure will be in infolded condition; but when the carton is erected, the closure will automatically come into position across the end of the carton. Y

Such a closure may be formed at one end only of the carton, or similar closures may be formed at both ends.-Y In 'this event, the formation of theV end seals will be effected as described above through the opening 28 in one of the body walls.

Where a gas tight structure is desired, I prefer to line the body walls with a suitable gas tight element. In Figure 8 I have shown one method of accomplishing this, wherein a sheet of suitable material such as parchment, foil, or one of the cellulosic films, coated with a preferably thermoplastic, gas tight adhesive, has been adhered to the inside surfaces of the body walls and glue lapwith a projection beyond the latter. This projection will be folded over and adhered to the outer surface of the glue flap. When such a treated carton is tubed with a suitable gas tight adhesive and with the glue flap inside, a gas tight longitudinal seal will be produced. If the carton is to be tubed with the glue ap outside, the projection of the sheet 35 may be paused to extend beyond the free edge of the wall I, and may be folded over and adhered against its outside surface.

The sheet or membrane 35 may be so dimensioned that its edges coincide With or lie slightly inwardly of the transverse score lines I4 and I5; but I prefer to extend the sheet beyond these score lines as shown in Figure 8a. It is essential that the end seal make good contact with the edges of the membrane at the ends of the carton and a projection of the sheet facilitates this. The projecting portions of the liner sheet 35 may either be left unadhered to the flaps, or the nature of the adhesive may be such that during the folding of the naps the liner will strip away from them sufficiently to permit such folding. Again, the projecting ends of the liner may be adhered to the wider flaps 1, 9, I I and I3 in areas such as those shaded and marked 9a and I3a in Figure 8a. The shorter flaps, such as those indicated at 8a and I2a in the figure need not extend substantially if at al1 beyond the projecting ends of the liner sheet. During the folding of the flaps, the projecting portions of the liner will form bellows-folds at the corners of the carton.

The formation of a gas-tight longitudinal carton seam may be accomplished in various ways. As shown in Figure 13, the glue flap 5 may be provided with an articulated extension 5a of the full length of the glue flap. The liner sheet 35 may be caused to cover both the glue nap and its extension as well as the body walls of the carton. Then, in tubing the carton the glue ap extension 5a is rst folded back and adhered against the glue flap. Next, the tubing of the carton is accomplished in the usual way, the result being a longitudinal glue seam in which the edges of the liner sheet are directly adhered together as will be clear from the drawing. A direct reversal of these parts would be to form the covered extension on the free edge of wall I, bend it back against this wall on the outside, adhesively securing it, and then tubing with the glue flap outside.

Again I may provide a lining by deposition upon the blank a preformed tube or bag of suitable gas tight or liquid tight substance. This may be done by using procedures and apparatus set forth in the Robert M. Bergstein Patents Nos. 2,250,249 and Re. 20,789. In Figure 9, I have shown a carton blank on which there has been deposited a tube 36 of suitable gas tight membranous material with a preformed. proof, longitudinal seam. The carton in this instance has been shown as having medial score lines 3l and 7 3B in the bodywalls 4 and 2. In tubing, the blank is bent along these score lines. This expedient is useful where one end of the tube, is preclosed to form a bag,but is not necessary where openl ended tubes are used.

The tube 36 may terminate at both ends adjacent the lateral-score lines I4 and I5 of the blank as shown atthe bottom of Figure8. However, for some uses I may wish to cause one end of the liner to project into and even beyond the flap area as shown at the top ofFgure 9.

Figure shows an end seal-formed in accordance with my invention in a lined carton such as that of Figure 8. It Will be noted that the interior end. coating of sealing substance 39 unites with the edge portions of the liner sheet 35. In connection with packages such'as are illustrated in Figures 8 to ll, where my object is to obtain dependable gas-tightness, I have found that an extreme fluidity of the sealing substance as it is injected into the carton end is highly desirable. The viscosity or iiuidity of the sealing substance does not appear so important where liquid-tightness alone is the quality desired; but in gas-tight cartons I have obtained uniformly superior results when I heat my sealing substances to temperatures materially higher--say 100 F. higher-than the lowest temperatures giving a good pouring consistency. I believe that the more thinly fluid the sealing substance is made the more perfectly it will penetrate into minor crevices in the structure to give dependable gas-tightness.

Where the liner has beenfcausedto project at the top end of the carton, as in Figure 9, a bottom closure end seal may be effected as illustrated in Figure 10 after -Which the Ycarton may be filled and the top end of the liner 36 closed with a seam V#l0 as shown in Figure '11. While this entails the closure andsealingof a liner end in ways hitherto current in the art for innerlined containers, my procedure presents the singular advantage ofV enabling me to carry on all operations in the carton-whilethe carton is in a single position. Thus the formation of the bottom seal, the filling of the carton, and the formation of the top seal are all accomplished while the carton is held-in an upright position. I am not required to send a carton in reversed positions twice through sealing and closing equipment, or to provide a duplication of closing and sealing equipment for the purpose.

It will be understood that when the top seal 40 has been eifected, the projecting end of the liner may be folded,and the end flaps of the carton folded and securedover it in ways known in the art. k

Where my cartons are made gas tight, and are to be gassed, I prefer to ll them with their contents and then close them in a gas tight fashion, prior to effecting change of atmosphere. Gassing may afterward be accomplished by. perforating the containers and either enclosing them in a vessel and successively vacuumizing and gassing them, or by introducing nozzle means into the containers and expelling the enclosed atmosphere by means ofthe desired protective gas. After either of these operations, the holes orperforations in the containers maybe sealed by covering them with a gas ltight web adhesively secured in place or by merely depositing over the perforations a quantity of softened thermoplastic sealing substance.

cartons are provided with' a filling opening they may-be gassed through this opening before application of the plug 25.

Figure 12 shows another way of forming an end seal in a'lined or unlined, lled carton. After the carton has been erected and closed and sealed at one end, it is thenlled with the contents 4|. Al platform-42 is placed across the end of the cartonand within the liner 35 if one is used. The coating 43 is formed above the platform so as to bond with the walls of the carton or with the liner as the case'may be. Afterward, if the carton has been provided with end closure flaps. these may be folded and secured in the usual fashion.

Modifications may be made in my invention Without departing from the spirit of it.

Having thus described my invention; what I claim as new and desire to secure by letters patent is:

1. A proofed paperboard structure comprisingV a paperboard carton having enclosing body walls in articulation and end closure flaps. said carton being in erected condition with the closure flaps closed across an end thereof, said carton being sealed interiorly at said closed end by thermoplastic sealing substance deposited on the closed end in a quantity suflicient to cover completely all inwardly exposed surfaces of the folded aps and to penetrate and seal all interstices therein, said deposit of thermo-plastic sealing substance being of solid block form extending continuously across the end of said carton from wall to wall forming an unobstructed imperforate inner surface contacting minor contiguous portions of said body walls, said deposit of thermoplastic sealing substance constituting a casting formed in situ in the carton on the closed end thereof. v

2. A proofed paperboard structure comprising a paperboard carton having enclosing body Walls in articulation and end closure flaps, said carton being inerected condition with the closure flaps closed across an end thereof, said carton being sealed interiorly at said closed end by thermoplastic sealing substance deposited on the closed end in a quantity sufficient to cover completely all inwardly exposed surfaces of the folded aps and to penetrate and seal all interstices therein, said deposit of thermoplastic sealing substance being of solid block form extending continuously across the end of said carton from Wall to wall forming an unobstructed imperforate inner surface contacting minor Vcontiguous portions of said body walls, said deposit of thermoplastic sealing substance constituting a casting formed in situ in the carton on the closed end thereof, said enclosing body walls being formed of pre-proofed paperboard.

3. A proofed paperboard structure comprising a paperboard carton having enclosing body walls in articulation and end closure flaps, said carton being in erected condition with the closure flaps closed across an end thereof, said carton being sealed interiorly at said closed end-by thermoplastic sealing substance deposited on the closed end in a quantity sufficient to cover completely allinwardly exposed surfaces of the folded flaps and to penetrate and seal all interstices therein, said deposit of thermo-plastic sealing substance being of solid block form extending continuously across the end of said carton from wall to wall forming an unobstructed imperforate inner surfacercontacting minor contiguous portions of said body walls, said deposit of thermoplastic sealing substance constituting a casting formed in situ in the carton on the closed end thereof, said enclosing body walls being lined with a proofed sleeve approaching said folded closure flaps, said casting making sealing contact with end portions of said proofed sleeve throughout its periphery.

4. A proofed paperboard structure comprising a paperboard carton having enclosing body walls in articulation and end closure flaps, said carton being in erected condition with the end closure flaps folded across the ends thereof, said carton being sealed interiorly at each end by thermoplastic sealing substance deposited on the interior ends of the carton in Quantities which cover completely all inwardly exposed surfaces of the folded flaps and to penetrate and seal all interstices therein, said deposits of thermoplastic sealing substance being of solid block form from wall to Wall extending continuously across the ends of the carton forming unobstructed imperforate inner surfaces contacting minor contiguous portions of said body walls, said deposits of thermoplastic sealing substance constituting castings formed in situ in the carton on the interior end surfaces thereof, said carton having a filling opening adapted to be closed by a plug, said filling opening being formed through the naps constituting one of said end closures and the casting of sealing substance covering said last mentioned end closure.

5. A proofed paperboard structure comprising a paperboard carton having enclosing body walls in articulation and end closure flaps, said carton being in erected condition with the end closure flaps folded across the ends thereof, said carton being sealed interiorly at each end by thermoplastic sealing substance deposited on the interior ends of the carton in quantities which cover completely all inwardly exposed surfaces of the folded flaps and to penetrate and seal all interstices therein, said deposits of thermoplastic sealing substance being of solid block form from wall to wall extending continuously across the ends of the carton forming unobstructed imperforate inner surfaces contacting minor contiguous portions of said body walls, said deposits of thermoplastic sealing substance constituting castings formed in situ in the carton on the interior end surfaces thereof, said carton having a lling opening adapted to be closed by a plug, said filling opening being formed through the flaps constituting one of said end closures and the casting of sealing substance covering said last mentioned end closure, the enclosing body walls of said carton being lined with a proofed sleeve approaching said folded flaps, said castings making sealing contact with end portions of said proofed sleeve throughout its periphery.

6. A proofed paperboard structure comprising a paperboard carton having enclosing body walls in articulation and end closure flaps, said carton being in erected condition with the end closure flaps folded across the ends thereof, said carton being sealed interiorly at each end by thermoplastic sealing substance deposited on the interior ends of the carton in quantities which cover completely all inwardly exposed surfaces of the folded flaps and penetrate and seal all interstices therein, said deposits of thermoplastic sealing substance being of solid block form from wall to wall extending continuously across the ends of the carton forming unobstructed imperforate inner surfaces contacting minor contiguous portions of said body walls, said deposits of thermoplastic sealing substance constituting castings formed in situ in the carton on the interior end surfaces thereof, a filling opening in one end of the carton, said filling opening extending through both the end closure ilaps and the casting of sealing substance covering said last mentioned end closure fiaps, and a closure for said lling opening.

7. A proofed paperboard structure comprising a paperboard carton having enclosing body Walls in articulation and end closure flaps, said carton being in erected condition with the closure flaps closed across an end thereof, said carton being sealed interiorly at said closed end by thermoplastic sealing substance deposited on the closed end in a quantity sufficient to cover completely all inwardly exposed surfaces of the folded flaps and to penetrate and seal all interstices therein. said deposits of thermoplastic sealing substance being of solid block form extending continuously across the end of said carton from Wall to wall forming an unobstructed imperforate inner surface contacting minor contiguous portons of said body walls, said deposit of thermoplastic sealing substance constituting a casting formed in situ in the carton on the closed end thereof, said enclosing body walls being lined with a proofed sleeve contacting said closed closure aps, said casting making sealing contact with end portions of said proofed sleeve through its periphery.

FRANK DAVID BERGSTEIN.

REFERENCES CKTED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,277,176 Bauer Aug. 27, 1918 1,856,743 Brooks May 3, 1932 1,912,698 1forsman June 6, 1933 2,025,477 Scott Dec. 24, 1935 2,105,025 Curtis Jan. 11, 1938 2,196,243 Bensel Apr. 9, 1940 2,261,621 Harrison Nov. 4, 1941 2,341,845 Mark et al Feb. 15, 1944 2,349,605 Becker May 23, 1944 2,411,622 Guyer et al Nov. 26, 1946 2,543,757 Bergstein Mar. 6, 1951 

